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The liquid electrolyte in conventional zinc/manganese dioxide (Zn/MnO2) batteries conduces to the capacity limitation of one‐electron redox from MnO2 to MnOOH, as well as undesired Mn loss with capacity deterioration. Herein, to conquer these challenges, a new idea is proposed on the precise proton redistribution in the hydrogel electrolyte for the preferred two‐electron redox reaction. Specifically, an acidic layer in the hydrogel adjoins the MnO2 cathode to maintain the two‐electron redox, a neutral layer adjoins the zinc anode to inhibit the dendrite growth, which is separated by a mildly alkaline layer to immobilize the proton distribution. The two‐electron redox of MnO2/Mn2+ and anode protection are demonstrated to play key roles in battery performance. Such a battery presents specific capacities of 516 mA h g−1 at 0.05 A g−1, as well as a capacity retention of 93.18% at 5 A g−1 after 5000 cycles without extra Mn2+ addition in the electrolyte. More importantly, fibrous Zn/MnO2 batteries using the tri‐layer electrolyte can sustain 2000 cycles with high initial capacity of 235 mAh g−1 at 1 A g−1. After 6000 times folding in 180°, it can maintain 99.54% capacity. When integrated into user's clothing or portable accessories, the fibrous battery is demonstrated as a great potential in wearable electronics. [ABSTRACT FROM AUTHOR]

Inspired by dual-signaling ratiometric mechanism which could reduce the influence of the environmental change, a novel, convenient, and reliable method for the detection of mercury ions (Hg 2+ ) based on Y-shaped DNA (Y-DNA) was developed. Firstly, the Y-DNA was formed via the simple annealing way of using two different redox probes simultaneously, omitting the multiple operation steps on the electrode. The Y-DNA was immobilized on the gold electrode surface and then an obvious ferrocene (Fc) signal and a weak methylene blue (MB) signal were observed. Upon addition of Hg 2+ , the Y-DNA structure was transformed to hairpin structure based on the formation of T-Hg 2+ -T complex. During the transformation, the redox MB gets close to and the redox Fc gets far away from the electrode surface, respectively. This special design allows a reliable Hg 2+ detection with a detection range from 1 nM to 5 μM and a low detection limit down to 0.094 nM. Furthermore, this biosensor exhibits good selectivity and repeatability, and can be easily regenerated by using l -cysteine. This study offers a simple and effective method for designing ratiometric biosensors for detecting other ions and biomolecules. [ABSTRACT FROM AUTHOR]

• The Fe2+/Fe3+ redox couple exhibits different quenching effects on the fluorescence of BSA/MPA-AuNCs. • Fe3+ can effectively suppress the PL of BSA/MPA-AuNCs, while Fe2+ shows low quenching efficiency. • In the presence of NO 2 − under acidic conditions, Fe2+ can be readily oxidized and transformed to Fe3+. • A facile and efficient assay for NO 2 − has been successfully developed. • This method can be suitable for determination of NO 2 − in ham samples. In recent years, gold nanoclusters (AuNCs) have received considerable attention as optical transducers in chemo/biosensors. Herein, a facile and efficient assay for NO 2 − has been successfully developed based on the fluorescence quenching of AuNCs co-modified by bovine serum albumin and 3-mercaptopropionic acid (BSA/MPA-AuNCs). In the presence of NO 2 − under acidic conditions, Fe2+ can be readily oxidized and transformed to Fe3+, which can significantly suppress the fluorescence of BSA/MPA-AuNCs via non-radiative electron-transfer mechanism. The linear range and detection limit for this system were found to be 5–30 μM (r = 0.9975) and 0.7 μM, respectively. Other common anions and cations showed only very minor interference with the NO 2 − detection. Furthermore, the effectiveness of the proposed sensing strategy was validated by the demonstration of good performance in the determination of the amount of NO 2 − in ham samples, rendering it a powerful tool for the assessment of food security and water quality. [ABSTRACT FROM AUTHOR]